SN74AHC14: 40M 5V input signal to 3.3V output, Schmitt-trigger device recommentdation

Yue TANG

Part Number: SN74AHC14
Other Parts Discussed in Thread: SN74LVC3G14

Hi,

My customer is checking with me a replacement. they used to use 74VHC14MX from fair child. but they need a upgraded device to handle a 40M 5v input signal,but the output is 3.3V . I found SN74AHC14 is a close one to 74HC14MX, but the Tpd is just the same level. would you please recommend a better device for this case? thanks. BTW, drop in replacement is better, TSSOP(14) package.

over 5 years ago

0 Clemens Ladisch over 5 years ago

Guru 273200 points

Fairchild's VHC and TI's AHC are pretty much equivalent, and support 70 MHz at 3.3 V.

There is no faster drop-in replacement. For different packages, look into the LVC family (e.g., 2× SN74LVC3G14).

What is the problem with the 74VHC14MX? Does it not handle the 40M signal? What is the output load capacitance?

0 Dylan Hubbard over 5 years ago in reply to Clemens Ladisch

TI__Mastermind 44610 points

Hi Yue,

The SN74AHC14DR would be an exact drop in replacement. If you want a TSSOP version, then you can go with SN74AHC14PWR. You can also check out the SN74LVC14APWR.

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SN74AHC14: 40M 5V input signal to 3.3V output, Schmitt-trigger device recommentdation